RNA interference (RNAi) is the process of effectively silencing or inhibiting the expression of target genes, which refers to the specific degradation of intracellular mRNA mediated by endogenous or exogenous double-stranded RNA (dsRNA). Thus, resulting in target gene silencing and corresponding loss of functional phenotype. RNAi, as a novel and powerful gene silencing tool, is widely used in biological and therapeutic research, especially for ineffective targets in the treatment of cancer and other diseases.

siRNA and miRNA Comparison

Similarities: The length of siRNA and miRNA are each about 22nt. Both are part of RISC components, with overlapping mechanisms to mediate silencing. Both depend on the processing of the Dicer enzyme, the products of the Dicer, and the characteristics of Dicer products. The production of siRNA and miRNA require the presence of Argonaute family proteins and the synthesis of miRNA and siRNA is formed by double-stranded RNA or an RNA precursor.
Differences: miRNA is endogenous and intrinsic to the organism, while siRNA is artificially synthesized in vitro and transfected into the human body as an intermediate product of RNA interference. miRNA mainly binds to the 3’UTR region of the target mRNA, while siRNA binds to any region that pairs with the target mRNA. miRNA mainly plays a role in the development process, regulating endogenous gene expression. However, siRNA is the product of RNAi and is not involved in biological growth. The role of siRNA is to inhibit transposon activity and viral infection.

RNAi Technology Applications

RNAi has high efficiency and simplicity in gene silencing, making it is a very important tool for gene function research. Most drugs are inhibitors of target genes, so RNAi mimics the effects of drugs. RNAi technology is commonly used in drug target discovery and confirmation. Biotech and pharmaceutical companies often use established RNAi libraries to transfect into cells to observe phenotypic changes in the cells to find functional genes. For example, tumor suppressor genes can be identified by RNAi library-mediated tumor cell growth. Once a gene is identified as a drug target, large-scale drug screening can be carried out against this target. Identified targets can be further identified at the cellular level or in animals using RNAi technology.
In terms of disease treatment, double-stranded small RNA or siRNA has been clinically tested for several diseases, such as age-related macular degeneration, amyotrophic lateral sclerosis, rheumatoid arthritis, obesity, and many more. With reference to antiviral therapy; neurologic diseases (such as Parkinson’s disease) are now being treated with RNAi therapy.

About us

Synbio Technologies provides customized siRNA synthesis products with different lengths, forms, and types of modifications and markers. siRNA can be detected by fluorescence microscopy and flow cytometry after terminal fluorescence labeling, which is convenient for the study of optimization of transfection and regulation of target protein expression.
Along with siRNA, we also offer a wide range of high quality miRNA synthesis products; including miRNA mimics/inhibitors, miRNA agomirs/antagomirs, and miRNA negative controls, to support your miRNA functional research.


Xu JZ, Zhang JL, et al. Antisense RNA: the new favorite in genetic research. J Zhejiang Univ Sci B. 2018 Oct.;19(10):739-749.

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